Salmonella Agona

Background: Salmonella enterica subsp. enterica serovar Agona (antigenic formula 1,4,[5],12:f,g,s:[1,2]) is a serovar of the O:4 (B) serogroup. Serovar Agona is among the 15^th most common serovars in humans the U.S., and the 4^th most common serovar in clinical non-human sources. This serovar was first isolated from cattle in Ghana in 1952, since then numerous outbreaks in the U.S. and Europe have occurred. Multi Locus Sequence Typing (MLST) has identified only four sequence types. Genome sequencing of 73 strains from multiple countries and sources was recently reported by Zhou et al., 2013.

Genetic characteristics: Whole genome sequences for 74 strains of S. Agona have been deposited at GenBank as of October, 2013. Genomic characteristics of the sequenced S. Agona include (i) a genome size ranging from 4.70 to 4.95 Mb, (ii) a mol G+C% of approx. 52, and (iii) 4,658 to 4,934 predicted genes. Comparative genomics of 73 of the sequenced strains identified three lineages of S. Agona that emerged approx. 80 years ago. S. Agona has an accessory genome of approx. 1.3 Mb; this accessory genome includes (i) multiple prophages (P2-like, Fels-like, Lambda-like), (ii) antibiotic resistance plasmids (e.g., IncI1 plasmids), (iii) genomic islands, (iv) transposons, and (v) chromosomal integrons.

Phylogenetic and pan-genomic analyses that included one of the sequenced S. Agona strains and other Salmonella serovars concluded that S. Agona belongs to clade A, according to den Bakker et al. (2011) classification and it contains 133 gene families unique to this serovar.

Animal reservoir: Different animal species, including turkey, swine and cattle are reservoirs of S. Agona.

Geographical distribution: Serovar Agona is among the most common serovars in North and South America, Europe, and Asia. In China, it is among the 10^th most common serovars.

Human outbreaks: Outbreaks linked to Salmonella Agona have been associated with different foods, including cereal, meat and fruits.

Year	Location	Associated source	Number of cases
2022	Sweden, Norway, Netherlands, & UK	Cucumbers (suspected)	107
2011	US-multistate	Imported Papayas	106
2008	US-multistate	Rice & Wheat Puff Cereal	28
2008	Europe (6 countries)	Meat, cocked sandwich	148
2008	Europe	Meat	119
2004	France	Infant formula	141
2002	Germany	Tea, aniseed herbal	42
1998	US: multistate	Toasted Oats Cereal	209

Border Rejections: Multiple border rejections associated with have been reported. Here we selected two as examples.

Year	Exporting country	Importing country	Associated source	Product category
2024	Poland	Italy	Turkey meat	Poultry meat and poultry meat products
2022	China	Sweden	Organic soybean cake	Feed materials

Recalls:

Year	Location	Recalled food	Type
2017	France	Infant formula¹	Ultra-processed food
1998	US: multistate	Toasted Oats Cereal²	Ready-to-Eat food

¹ This recall was caused by an outbreak of Salmonella enterica serovar Agona associated with infant formula products manufactured by the Lactalis Nutrition Santé group in France.

² This recall was caused by an multistate outbreak of Salmonella serovar Agona infections linked to toasted oats cereal manufactured by Malt-O-Meal.

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Salmonella Agona